There are many uses for thermal insulation that do not require any physical attributes from the insulating material except the ease of use and the thermal properties of the insulating material itself. For example, houses and other buildings can be insulated with sheets of rigid plastic foam which can be tacked to the exterior frame of the house before the siding is placed on the house. In another example, the interior of houses can be insulated because their very construction allows for the placement of insulating batting or beaded or particulate materials in existing chambers such as on top of ceilings, between ceiling joists, in walls between wall studs, and the like.
However, there are also a multitude of uses in which the insulating material cannot be used unless it is modified or configured to fit the particular end use. Examples of such uses can be found for example in U.S. Pat. No. 3,707,850 to Connell, et al, which issued on Jan. 2, 1973, in which insulating material is bagged up in small bags, and a multitude of these bags are layered to insulate a chamber placed in the earth.
Another special configuration to provide insulation to a substrate can be found in an abstract from Derwent Publications Ltd. 86-156540/25, abstracting German patent 444,728, in which polystyrene foam sheets are prepared having at least one corrugated surface in order to fit the corrugated surface of a roof. The polystyrene sheet in then top coated with concrete to hold it in place.
A further publication of special insulation can be found in 1987 Derwent Publications 87-178862/26 abstracting German patent DE 546,032, in which prefabricated rectangular panels, each having a core made of hard plastic foam materials, preferably polystyrene, are used to cover a roof made of corrugated asbestos cement sheets.
Yet another approach to insulating an embankment foundation for liquid storage, especially in cold climates such as Alaska, is shown in U.S. Pat. No. 3,846,989, issued to Burt, et al, on Nov. 12, 1974. The so-called "Arco" insulation is a foamed-in-place polyurethane insulation layer that is sprayed directly on the substrate and allowed to foam and cure. No coverings or carriers for this foam are disclosed or shown.
The Burt et al patent describes in intimate detail, the problems associated with attempts to insulate portions of the earth's substrate. The invention disclosed herein, in it's various embodiments, overcomes many of the problems described by Burt et al.
In order to service those activities associated with the insulation of the earth's surface, the materials used must have sufficiently low thermal conductivity and/or sufficient thickness to protect the soil from freezing or reaching hot temperatures. The materials must have sufficient strength and durability to withstand the rigors of installation and use and must be resistant to weathering, including precipitation, wind, ultraviolet radiation, and temperature extremes. The material must be cost effective and must be simple to produce, install, remove if it is no longer needed, and re-use if it is needed elsewhere. Installation and removal should pose a minimum of disruption to existing operations and construction practices. The material should be capable of being installed and removed without damage to the underlying substrate and finally, the installation and use of the material should minimize risks to the health and safety of personnel using the material.